Device for obtaining a desalinated solution

ABSTRACT

A device for producing a permeate from a concentrate has a separating chamber and a filter membrane dividing the separating chamber into a concentrate chamber and a permeate chamber. An inlet line is connected to the concentrate chamber and introduces the concentrate into the concentrate chamber. A concentrate line is branched off the concentrate chamber and has a control valve. A permeate line is branched off the permeate chamber. An accumulator is connected to the permeate line. A non-permeable separating membrane divides the accumulator into a storage chamber and a pressurized chamber, wherein the storage chamber is connected to the permeate line and the pressurized chamber is connected to the control valve of the concentrate line. The control valve is a jet nozzle and has a jet head, wherein the concentrate line opens into the jet head. An outlet concentrate line is connected to the jet nozzle opposite the concentrate line at a spacing to the jet head, wherein the jet head of the nozzle issues an accelerated exit jet entering the outlet concentrate line. The jet nozzle has an under pressure chamber surrounding the exit jet. A suction line branches off the under pressure chamber of the jet nozzle and is connected to the pressurized chamber.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a device for obtaining a permeate from aconcentrate, in particular, raw water comprised of a separating chamberwhich is divided by a filter membrane into a concentrate chamber and apermeate chamber with an inlet line opening into the concentrate chamberfor the concentrate and a concentrate line branched off the concentratechamber as well as a permeate line branching off the permeate chamber,to which is connected an accumulator which is divided by a non-permeableseparating membrane into a storage chamber and a pressurized chamber,wherein the storage chamber is connected to the permeate line and thepressurized chamber is connected via a control valve to the concentrateline.

2. Description of the Related Art

Especially in areas close to the ocean, the raw water provided tohouseholds has a high salt content based on which all needs in regard tothe use of the raw water cannot be satisfied. The thus requiredtreatment of the raw water is carried out in devices which have aseparating chamber with a membrane module which by means of a separationmethod such as, for example, reverse osmosis divides the raw water intoa concentrated solution (concentrate) and a desalinated solution(permeate). The salt molecules of the raw water in this case cannotovercome the osmotic membrane even under pressure and remain thus in theconcentrate. Accordingly, the permeate filtered through the membraneremains substantially free of salt molecules.

From DE 39 14 940 A1 a device of the aforementioned kind for treatmentof raw water is known. By means of switchable valves permeate isobtained when removing raw water which, with displacement of fillingwater, flows into an accumulator. For the removal of permeate, severalvalves must be switched which is technically complex and cumbersome. Inthis connection, the raw water line is connected with the filling watervolume so that the permeate flows out of the accumulator substantiallyunder the line pressure. The permeate is generated in the low-pressurerange which results in only a minimal permeate yield.

Reverse osmosis in the low-pressure range is also used in the deviceaccording to DE 195 45 277 A1 which has the consequence that thepermeate yield is low in comparison to the concentrate. As demonstratedin practice, in the low-pressure range 5-20% of the supplied raw wateris obtained as permeate. This permeate flows into a permeate storagedevice which must be designed such that it can also cover adiscontinuous increased permeate demand. The minimal permeate yieldresults in that the concentrate differs with regard to quality onlyminimally from the raw water and can thus be used for many applicationsin the household such as washing dishes and cleaning withoutreservations. As a result of the minimal permeate yield in thelow-pressure range a large amount of raw water is required which usuallyflows out as waste water without having been used.

From Japanese laid open patent JP-62-91204 it is known to arrange anoutflow vessel at the filter outlet for enhancement of the filter outputwhose airspace above the liquid level is loaded by under pressure bymeans of a jet pump. The jet pump is arranged within the concentratecircuit which is also operated by a pump.

SUMMARY OF THE INVENTION

It is an object of the invention to further develop a device of theaforementioned kind such that the production and making available ofpermeate, for example, as drinking water, is possible with minimalenergy consumption and raw water use.

The object is solved according to the invention in that the concentrateline opens into the jet head of a jet nozzle whose accelerated exit jetenters into an outlet concentrate line positioned at a distance oppositethereto, and in that a suction line is branched off an under pressurechamber of the jet nozzle surrounding the exit jet and is connected withthe pressurized chamber.

The selection of an accumulator whose pressurized chamber is connectedwith the concentrate line by a jet nozzle combines storage andconveyance of the permeate in the permeate network within a singledevice. In this connection, the under pressure or over pressure in thepressurized chamber is derived solely from the water supply network. Thealternating switching between generation of an under pressure or an overpressure is realized by the user when selecting concentrate consumptionor permeate consumption.

When concentrate is being consumed, the concentrate flows from theconcentrate chamber of a separating chamber and reaches via aconcentrate line a jet head of the jet nozzle. The accelerated exit jetgenerates upon entering a line positioned opposite the jet head at aspacing thereto a pressure drop in its immediate vicinity. The couplingof the under pressure chamber of the jet nozzle comprising the exit jetto the pressurized chamber of the accumulator makes it possible toemploy this pressure drop as a suction effect. Upon simultaneous outflowof the concentrate, the pressurized chamber of the accumulator which iscoupled with the jet nozzle and is filled correspondingly with theconcentrate, is emptied by suction. Since the pressure membrane of theaccumulator yields to the pressure, the suction effect is transmittedonto the oppositely positioned chamber which is connected via thepermeate line with the permeate chamber of the separating chamber andthus increases the pressure gradient via the membrane and thus also thepermeate yield. The emptying of the pressurized chamber of theaccumulator filled with concentrate is coupled with the filling of theoppositely positioned storage chamber with the permeate. Solely by thepressure which is present within the water supply network of the watersupply line, the under pressure in the accumulator is achieved withoutadditional pump devices.

The connection of the permeate chamber of the separating chamber withthe accumulator makes an increase of the permeate yield possible. Whenan under pressure is present in the accumulator, the permeate is suckedin from the permeate chamber of the separating chamber. The underpressure in the accumulator is distributed within the permeate chamberand increases the efficiency of the separating membrane in theseparating chamber. The concentrate can further be used as general usewater because the separation is carried out in the low-pressure range.The concentrate differs slightly from the raw water and can therefore beused without problems for flushing processes in the household. Duringconsumption of concentrate or raw water, the permeate is produced andcollected in the accumulator. When the permeate is used in thehousehold, the user switches the mixed water faucet to the permeateline. The accumulator in emptied from the permeate contained in thestorage chamber, additionally enhanced by the static over pressure ofthe concentrate, which is built up within the accumulator via theconcentrate line connected to the jet nozzle.

According to a further development of the invention, an additionalseparating chamber is connected to the concentrate line downstream ofthe jet nozzle. Its corresponding permeate chamber is connected with thestorage chamber of the accumulator. Operating this additional separatingchamber is realized by means of controlling an inlet valve which ismounted in the concentrate line for supplying the separating chamber.The control is connected with a switching contact connected with thepressurized chamber which controls opening of the inlet valve as afunction of the filling amount in the storage chamber. For this purpose,a magnet is mounted on the pressure membrane at the side of the storagechamber via which a switching contact can be actuated in a contactlessway for switching the inlet valve when an increased permeate demand ispresent.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawing one embodiment of the invention explained in thefollowing is schematically illustrated. It is shown in:

FIG. 1 a schematic illustration of a device for producing permeate withoutflowing concentrate;

FIG. 2 a schematic illustration of a device for producing permeate withoutflowing permeate.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The device 1 for producing permeate and schematically illustrated inFIGS. 1 and 2 comprises a separating chamber 2 formed as a membranemodule which is divided by an separating membrane 3 into a concentratechamber 4 and a permeate chamber 5. The concentrate chamber 4 isconnected by means of an inlet line 6 with a water supply network 7 viawhich the volume flow of raw water flows in the direction of arrow 8.

A concentrate line 9 branches off the concentrate chamber 4 and opensinto a jet head 9 b a of a jet nozzle 10. Opposite the jet head 9 b aline 11 is present which is conducted to the fixture 12, for example, amixed water faucet. When the switching section 13 of the fixture 12 isswitched to the concentrate line 11, the concentrate flows in thedirection of arrow 9 a out of the jet head 9 b into the oppositelypositioned concentrate line 11.

The permeate chamber 5 is connected by means of a permeate line 17 withan accumulator 19. The check valve 16 arranged therebetween protects theseparating membrane 3 of the separating chamber 2 against counterpressures. It allows only outflow of the permeate from the permeatechamber into the permeate line 17 according to the direction of arrow 17a.

In the accumulator 19 the permeate chamber 21 provided for the permeateis delimited by a non-permeable pressure membrane 20. The remainingpressurized chamber 22 of the accumulator 19 is connected by a line 23via the jet nozzle 10 with the concentrate line 9.

When consuming concentrate or raw water, under pressure results in thespace 10 a of the jet nozzle 10 surrounding the exit jet 10 b and sucksin the raw water 22 from the accumulator 19 via the line 23 in thedirection of arrow 23 a. Via the pressure membrane 20 an under pressureis built up in the permeate chamber 21 of the accumulator 19 so that thepermeate is sucked in via the permeate line 17.

Accordingly, the accumulator 19 is filled with permeate while theconcentrate flows out.

The separating membrane to be provided in the separating chamber 2 isselected according to the operational conditions with regard to theseparating quality. For example, a reverse osmosis membrane, ananofiltration membrane, an ultrafiltration membranes or amicrofiltration membrane can be used. They all operate in thelow-pressure range. In the concentrate chamber 4 preferably a maximumpressure which is the same as in the water supply network 7 is present.Despite the low-pressure of less than 10 bar, expediently 2 to 4 bar, asufficient permeate yield is obtained. The predominant part of the rawwater, flowing in via the inlet line 6, flows out of the water faucet 15via the concentrate lines 9 and 11 in the direction of arrow 15 a. Eventhe increased permeate yield still allows the use of concentrate asgeneral use water. Should there be an increased demand of raw water, viaan inlet line 26 additional raw water can be supplied and metered by aninlet valve 27.

There is also a possibility provided to mix hot water with raw water byconnecting a hot water line 14 to the fixture 12.

For the consumption of permeate, the armature or fixture 12 is movedinto the switching position 13′, for example, by turning the mixed waterfaucet. In this switched position the concentrate line 11, optionallywith the aid of an inlet valve 25, is closed and the line 24 isconnected by the branch line 18 with the permeate line 17. Since waterflows still from the water supply network 7 in the direction of arrow 8into the concentrate chamber 4, the concentrate will flow from the jethead 9 b into the chamber 10 a of the jet nozzle 10 and via the line 23in the direction of arrow 23 b into the accumulator 19. The pressure ofthe water supply network 7, which is built up via of the concentrateline 9 and line 23, acts in the direction of arrow 22 a onto thepressure membrane 20. The permeate in the accumulator 19 flows under thepressure of the water supply network 7 via the permeate line 17 in thedirection of arrow 17 b to the branch line 18 and via the line 24 to thewater faucet 15. With the arrangement of a check valve 16 at the exit ofthe permeate chamber 5 it is prevented that permeate can flow back intothe permeate chamber 5. Up to the point of complete emptying of theaccumulator 19 the concentrate continues to flow into the pressurizedchamber 22.

Once the consumer has removed a sufficient amount of permeate or oncethe accumulator 19 is empty, the consumer will close the fixture 12 orswitch back to previous switching position 13. When opening the waterfaucet 15, concentrate will flow again.

In order to cover cases of increased permeate consumption, an additionalseparating chamber 2′ can be connected to the concentrate line by meansof an additional concentrate line 28 downstream of the jet nozzle 10.The inflowing volume flow of the concentrate, flowing in the directionof arrow 28 a, is controlled by an inlet valve 29 arranged in theadditional concentrate line 28. The separating chamber 2′ is divided bya separating membrane 3′ into a concentrate chamber 4′, to which isconnected a wastewater line 34, and a permeate chamber 5′. The permeatechamber 5′ is protected against counter pressures by a check valve 35and connected by a line 31 with the permeate chamber 21 of theaccumulator 20. The inlet valve 29 is connected by a control line 30with a switching contact at the sidewall of the permeate chamber 21. Onthe pressure membrane 20 a magnet 33 is arranged at the side of thestorage chamber 21 which actuates the switching contact 32. The openingof the inlet valve 29 is realized as a function of the filling level inthe permeate chamber 21. Starting at a certain removal quantity, themagnet 33 reaches the vicinity of the switching contact 32 and effectsin a contactless way the switching of the inlet valve 29. The switchingpoint is determined by the arrangement of the switching contact 32 andof the magnet 33. The opening of the inlet valve 29 results in asupplemental production of permeate via the additional separatingchamber 2′. The concentrate flows out via the wastewater line 34.

Optionally, the additional concentrate line 28 can also open downstreamof the inlet valve 29 directly into a wastewater line 36. Due to theoutflow of concentrate, raw water flows into the concentrate chamber 4and via the jet nozzle 10 into the additional line 28 so that permeateis produced in the separating chamber 2.

The arrangement of a jet nozzle 10 has the advantage that the permeatecan be produced, stored, and conveyed only by the pressure which is madeavailable through the water supply network 7. No additional energy for apressure increases required.

The device 1 according to the invention can be adapted to the typicalconditions of a household in that the separating chamber and theaccumulator 19 can be accordingly sized in order to cover the dailypermeate demand. As illustrated in FIGS. 1 and 2, the device 1,comprised of the separating chamber 2, the jet nozzle 10, theaccumulator 9, and optionally the additional separating chamber 2′ withthe connecting lines, respectively, is embodied as a constructionmodule, which is arranged in the completely mounted state at thelocation of use, for example, underneath a kitchen sink. For beginningoperation of the device 12, the inlet line 6 must be connected to thewater supply network and the lines 11 and 24 to the fixture 12.

For controlling the concentrate inflow 6, a pressure-controlled valve 50can be provided whose actuation unit 52 is controlled via a pressureline 51 by the pressure in the permeate line 17. When in the permeateline 17 a pressure is generated, the inlet valve 50 is closed uponreaching a threshold value. When a pressure drop occurs in the permeateline 17, which can happen, for example, when opening the fixture 12, theinlet valve 50 is opened again and the separating chamber 2 begins tooperate again.

What is claimed is:
 1. A device for producing a permeate from aconcentrate, said device comprising: a separating chamber (2); a filtermembrane (3) dividing said separating chamber (2) into a concentratechamber (4) and a permeate chamber (5); an inlet line (6) connected tosaid concentrate chamber (4) and configured to introduce the concentrateinto said concentrate chamber (4); a concentrate line (9) branched offsaid concentrate chamber (4) and comprising a control valve (10); apermeate line (17) branched off said permeate chamber (5); anaccumulator (19) connected to said permeate line (17); a non-permeableseparating membrane (20) dividing said accumulator (19) into a storagechamber (21) and a pressurized chamber (22), wherein said storagechamber (21) is connected to said permeate line (17) and saidpressurized chamber (22) is connected to said control valve (10) of saidconcentrate line (9); said control valve (10) being a jet nozzle andhaving a jet head (9 b), wherein said concentrate line (9) opens intosaid jet head (b); an outlet concentrate line (11) connected to said jetnozzle (10) opposite said concentrate line (9) at a spacing to said jethead (9 b), wherein said jet head (9 b) of said nozzle (10) issues anaccelerated exit jet (10 b) entering said outlet concentrate line (11);said jet nozzle (10) having an under pressure chamber (10 a) surroundingsaid exit jet (10 b); a suction line (23) branched off said underpressure chamber (10 a) of said jet nozzle (10) and connected to saidpressurized chamber (22).
 2. The device according to claim 1, whereinthe pressure in said pressurized chamber (22) is within a low-pressurerange.
 3. The device according to claim 1, comprising a common fixture(12) for dispensing the permeate and the concentrate and comprising anoutlet permeate line (24) branched off said permeate line (17), whereinsaid concentrate line (11) and said outlet permeate line (24) open intosaid common fixture (12) which comprises a water outlet (15).
 4. Thedevice according to claim 3, comprising a hot water line (14) openinginto said fixture (12), wherein said hot water line (14) can be coupledto an outlet of said water outlet (15).
 5. The device according to claim1, comprising a check valve (16) arranged between said permeate chamber(5) and said storage chamber (21) and opening in a direction toward saidstorage chamber (21).
 6. The device according to claim 1, wherein saidinlet line (6) is a line of a water supply network (7) and whereinmaximally a water pressure of said supply network (7) is present in saidconcentrate chamber (4).
 7. The device according to claim 1, comprisingan additional separating chamber (2′) with a filter membrane (3′)dividing said additional separating chamber (2′) into an additionalconcentrate chamber (4′) with an additional concentrate line (28),having an inlet valve (29) and being connected to said outletconcentrate line (11), and into an additional permeate chamber (5′)having an additional permeate line (31) connected to said storagechamber (21), wherein said additional concentrate chamber (4′) has abranched-off wastewater line (34), and wherein a volume flow of theconcentrate flowing in said additional concentrate line (28) into saidadditional permeate chamber (4′) is controlled by said inlet valve (29).8. The device according to claim 7, comprising a switching contact (32)arranged at an outer side of said storage chamber (21) and having acontrol line (30) coupling said switching contact (32) to said inletvalve (29), wherein said switching contact (32) opens or closes saidinlet valve (29) as a function of a filling level of said storagechamber (21).
 9. The device according to claim 8, comprising a magnet(33) mounted on said separating membrane (20), wherein said switchingcontact (32) is switched by said magnet (33) in a contactless way,wherein a position of at least one of said magnet (33) and saidswitching contact (32) is based on a desired filling level of saidstorage chamber (21).
 10. The device according to claim 7, wherein saidfilter membrane (3, 3′) of said separating chamber (2) and saidadditional separating chamber (2′) are selected from the groupconsisting of a reverse osmosis filtration membrane, a nanofiltrationmembrane, an ultrafiltration membrane, and a microfiltration membrane.11. The device according to claim 7, wherein said separating chamber(2), said permeate line (17), said accumulator (19), said jet nozzle(10), and said additional separating chamber (2′) are combined in aconstruction module (1).
 12. The device according to claim 1, whereinsaid separating chamber (2), said permeate line (17), said accumulator(19), and said jet nozzle (10) are combined in a construction module(1).
 13. The device according to claim 1, comprising a direct connection(26) with an inlet valve (27) branching off said inlet line (6) to saidoutlet concentrate line (11).
 14. The device according to claim 1,comprising a common fixture (12) for dispensing the concentrate and thepermeate, wherein said fixture (12) has a control valve (25) configuredto mix the concentrate into the permeate.